The xtheorem package

Transcription

1 The xtheorem package AB 2008/08/03 Contents 1 Interfaces The Template Type theoremstyle The Template std (type theoremstyle) Implementation 3 Abstract This is a conversion of the AMS theorem classes to the template system. Only the interface was changed, the internals still use L A TEX 2ε commands. 1 Interfaces 1.1 The Template Type theoremstyle Arg: 1 Text of the number of the theorem (e.g., A.1), or \NoValue to indicate that the theorem is unnumbered. Arg: 2 Name of the theorem (e.g. Theorem, Lemma). Arg: 3 Additional note (e.g. see [12]), or \NoValue. Semantics: This template starts a new environment, typesets the head of a theorem, and sets fonts for the body of the theorem. The environment is ended by an \@endtheorem command. If the first argument is given, it is printed as the number part. The second argument contains the name of the theorem, and the third one may contain an additional note. For instance, the arguments 2.1, Lemma, and Rabin~1960 could produce the output This file has version number 754, last revised 2008/08/03. 1

2 Lemma 2.1 (Rabin 1960). where the following text is set in italic. 1.2 The Template std (type theoremstyle) Attributes: pre-skip (l) Skip above the theorem. post-skip (l) Skip below the theorem. Default: topsep Default: topsep body-style (f0) Commands to be executed before the body of the theorem in order to set fonts, etc. Default: italic head-style (f0) Commands to set the font of the head. Default: bold note-style (f0) Commands to set the font of the note. Default: medium upright font head-punct (f0) Text after the head. Default:. head-format (f3) Format of the head. head-indent (l) Indent of the head. head-sep (l) Space after the head. Default: Name Number (Note) Default: none Default: 5pt ± 1pt post-head-action (f0) Command to be executed after the head (e.g., a line break). Default: none Semantics & Comments: This are all parameters provided by the AMS package, except swaphead which can be simulated by head-format. \newtheorem Problem. The current solution for head-format is very clumsy. Perhaps it would be better to pass just the name of a template which does the layout instead of the actual code. The \newtheorem command defines a new type of theorem. It takes the following arguments: \newtheorem[*] style name [share counter] label [count relative] and defines an environment named name. meanings: The arguments have the following * If present the theorem is unnumbered, otherwise it is numbered. 2

3 style The name of an instace of the theoremstyle template which is used to typeset the theorem. name The name of the new environment. share counter (optional) The label of another defined theorem. If present both kinds of theorem share a common counter. label The name of the theorem which should appear in its head. count relative If present the counter is reset to 1 everything the counter with this name is changed (e.g., section or chapter). For instance, the following definitions create environments named Thm, Prop, Lem, Cor, Def, Rem, and Exam. The first five share a common counter which is relative to the current section, the last two are unnumbered. \newtheorem{plain}{thm}{theorem}[section] \newtheorem{plain}{prop}[thm]{proposition} \newtheorem{plain}{lem}[thm]{lemma} \newtheorem{plain}{cor}[thm]{corollary} \newtheorem{definition}{def}[thm]{definition} \newtheorem*{remark}{rem}{remark} \newtheorem*{remark}{exam}{example} 2 Implementation 1 package 2 \ProvidesExplPackage 3 {\filename}{\filedate}{\fileversion}{\filedescription} 4 \RequirePackage{xparse} 5 \RequirePackage{template} 6 \DeclareTemplateType{theoremstyle}{3} 7 8 \skip_new:n \TS_pre_skip 9 \skip_new:n \TS_post_skip 10 \dim_new:n \TS_head_indent_dim 11 \skip_new:n \TS_head_sep_skip \DeclareTemplate{theoremstyle}{std}{3} 14 { 15 pre-skip =l [\DelayEvaluation{\topsep}] \TS_pre_skip, 16 post-skip =l [\DelayEvaluation{\topsep}] \TS_post_skip, 17 body-style =f0 [\itshape] \TS_body_style_tlp, 18 head-style =f0 [\bfseries] \TS_head_style_tlp, 19 note-style =f0 [\fontseries\mddefault\upshape] \TS_note_style_tlp, 20 head-punct =f0 [.] \TS_head_punct_tlp, 21 head-format =f3 [\IfNoValueF{#1}{#1\IfNoValueF{#2}{\space}} 3

4 22 \IfNoValueF{#2}{\textup{#2}} 23 \IfNoValueF{#3}{\space{\TS_note_style_tlp(#3)}}] 24 \TS_head_format:nnn, 25 head-indent =l [0pt] \TS_head_indent_dim, 26 head-sep =l [5pt plus 1pt minus 1pt] \TS_head_sep_skip, 27 post-head-action =f0 [] \TS_post_head_action_tlp 28 } 29 { 30 \DoParameterAssignments 31 \if_mode_horizontal: 32 \prg_whiledo:nt{ 33 \int_compare:nnnt \etex_lastnodetype:d = \c_eleven 34 }{\tex_unskip:d} 35 \par 36 \fi: 37 \normalfont 38 \trivlist 39 \let:nn\thmheadnl\scan_stop: 40 \@topsep\ts_pre_skip 41 \@topsepadd\ts_post_skip 42 \IfNoValueF{#1} 43 {\refstepcounter{#1}} 44 \deferred@thm@head{ 45 \TS_head_style_tlp 46 \skip_horizontal:n \TS_head_indent_dim 47 \IfNoValueTF{#1} 48 {\TS_head_format:nnn{#2}{#1}{#3}} 49 {\TS_head_format:nnn{#2}{\cs_use:c{the#1}}{#3}} 50 \TS_head_punct_tlp 51 \TS_post_head_action_tlp 52 \skip_horizontal:n\ts_head_sep_skip 53 } 54 \TS_body_style_tlp 55 \ignorespaces 56 } These functions are used by the template above. They are copied straight away from amsclass.dtx. 57 \let:nn\adjust@parskip@nobreak \@nbitem 58 \toks_new:n\dth@everypar 59 \toks_set:nn \dth@everypar{ 60 \@minipagefalse 61 \global\@newlistfalse 62 \if@inlabel 63 \global\@inlabelfalse 64 \begingroup 65 \setbox\z@\lastbox 66 \ifvoid\z@ \kern-\itemindent \fi 67 \endgroup 68 \unhbox\@labels 4

5 69 \fi \else \everypar{} 76 \fi 77 } 78 \def\deferred@thm@head#1{% 79 \if@inlabel \indent \par \fi % eject a section head if one is pending 80 \if@nobreak 81 \adjust@parskip@nobreak 82 \else 83 \addpenalty\@beginparpenalty 84 \addvspace\@topsep 85 \addvspace{-\parskip}% 86 \fi 87 \global\@inlabeltrue 88 \everypar\dth@everypar 89 \sbox\@labels{\normalfont#1}% 90 \ignorespaces 91 } The usual styles plain, definition, and remark. 92 \DeclareInstance{theoremstyle}{plain}{std}{} \DeclareInstance{theoremstyle}{definition}{std} 95 { 96 body-style = \normalfont 97 } \DeclareInstance{theoremstyle}{remark}{std} 100 { 101 pre-skip = \DelayEvaluation{0.5\topsep}, 102 post-skip = \DelayEvaluation{0.5\topsep}, 103 body-style = \normalfont, 104 head-style = \itshape 105 } The command to end a theorem. 106 \def:npn\@endtheorem{\endtrivlist\@endpefalse } newtheorem just checks all cases and defines the appropriate environment. 107 \DeclareDocumentCommand{\newtheorem}{smmomo} 108 { 109 \exp_args:nc\@ifdefinable{#3} 110 { 111 \IfBooleanTF{#1} 112 { 113 \DeclareDocumentEnvironment{#3}{o} 5

6 114 {\UseInstance{theoremstyle}{#2}{\NoValue}{#5}{##1}} } 117 { 118 \IfNoValueTF{#4} 119 { 120 \IfNoValueTF{#6} 121 { 122 \newcounter{#3} 123 } 124 { 125 \newcounter{#3}[#6] 126 \gdef:cpx{the#3}{\exp_not:c{the#6} 127 \@thmcountersep\@thmcounter{#3}} 128 } 129 \DeclareDocumentEnvironment{#3}{o} 130 {\UseInstance{theoremstyle}{#2}{#3}{#5}{##1}} 131 {\@endtheorem} 132 } 133 { 134 \cs_if_free:ctf{c@#4} 135 { 136 \@nocounterr{#4} 137 } 138 { 139 \gdef:cpx{the#3}{\exp_not:c{the#4}} 140 \DeclareDocumentEnvironment{#3}{o} 141 {\UseInstance{theoremstyle}{#2}{#4}{#5}{##1}} 142 {\@endtheorem} 143 } 144 } 145 } 146 } 147 } 148 \endinput 149 /package 6